TL;DR: The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Chemistry to Henri B. Kagan and Kenso Soai for discoveries showing how chemical reactions can produce just one mirror-image molecule.

Academy names two laureates in Stockholm

The Royal Swedish Academy of Sciences decided to award the Nobel Prize in Chemistry 2026 to Henri B. Kagan of Université Paris-Sud in France and Kenso Soai of Tokyo University of Science in Japan, according to NobelPrize.org.

The Academy announced the decision on Oct. 7, 2026. The citation honored the pair “for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis,” according to NobelPrize.org.

Reuters reported the announcement from Stockholm on Oct. 7 and described the award as honoring French and Japanese scientists for work on so-called mirror-image molecules.

The Associated Press also reported that Kagan and Soai won the chemistry prize on Wednesday for work aimed at resolving mysterious mirror images in chemical molecules.

The prize amount is 12 million Swedish kronor to be shared equally between the laureates, according to NobelPrize.org. The Royal Society of Chemistry reported the sum as equivalent to £904,000 and said each laureate also receives a diploma and a medal.

Who the winners are

Henri B. Kagan was born in 1930 in Boulogne-Billancourt, France, according to NobelPrize.org. He earned a PhD in 1960 from Collège de France and became Professor Emeritus at what was then Université Paris-Sud, according to NobelPrize.org.

Kenso Soai was born in 1950 in Hiroshima, Japan, according to NobelPrize.org. He earned a PhD in 1979 from the University of Tokyo and became Professor Emeritus at Tokyo University of Science, according to NobelPrize.org.

AFP reported their ages at the time of the award as 95 for Kagan and 76 for Soai. AFP identified Kagan as professor emeritus at Université Paris-Saclay and Soai as a professor at Tokyo University of Science.

France’s CNRS said Kagan devoted much of his career to molecular chirality within the Molecular Catalysis team at the Institute of Molecular Chemistry and Materials of Orsay, operated by Université Paris-Saclay and CNRS.

CNRS said Kagan graduated from the École Nationale Supérieure de Chimie de Paris and began his career at CNRS in 1954. He completed his PhD at Collège de France under the supervision of Jean Jacques, according to CNRS.

CNRS said he was appointed lecturer at Université Paris-Saclay, formerly Université Paris-Sud, in 1967 and promoted to full professor in 1973. He became a professor at the Institut Universitaire de France in 1993, according to CNRS.

CNRS said he has been a member of the French Academy of Sciences since 1991 and was made an Honorary Fellow of the Royal Society of Chemistry in 2002.

What homochirality means

Some molecules, such as amino acids, exist as two variants that are each other’s mirror image, according to NobelPrize.org. Living organisms contain only one of these mirror images, according to NobelPrize.org.

Life’s chemistry is described as homochiral, from Greek words for “same” and “hand,” according to NobelPrize.org. Like hands, all amino acids exist as two mirrored variants, but only one occurs in proteins in human cells, while the other is rarely found in nature, according to NobelPrize.org.

The Royal Swedish Academy of Sciences’ popular background material said DNA also illustrates the pattern because sugar molecules in DNA have two mirror images, but life uses one, as summarized by reporting from the Academy material.

Chemists long wondered how homochirality could emerge, according to NobelPrize.org. When they ran reactions that could form two mirrored molecules, test tubes consistently yielded equal proportions of both, according to NobelPrize.org.

Researchers nevertheless sought methods that would produce only one mirror image, especially for molecules intended to interact with living beings, such as pharmaceuticals, where only one mirror image produces the intended effect, according to NobelPrize.org.

Heiner Linke, chair of the Nobel Committee for Chemistry, said Kagan and Soai supplied an answer to a puzzle more than a century old concerning how homochirality can appear spontaneously, according to NobelPrize.org. Linke called the chemical reactions they developed spectacular, according to NobelPrize.org.

Why drugmakers care about handedness

Many drug molecules occur in two variants that are non-identical mirror images, according to the Royal Society of Chemistry. One variant can supply a therapeutic effect, while the other can cause unnecessary and sometimes harmful side effects, according to the Royal Society of Chemistry.

The Academy used a locksmith comparison to explain the challenge, according to AFP. The problem resembles a locksmith who always produces two mirrored keys when only one fits a lock, while the wrong key may damage the lock, according to AFP.

Phillip Broadwith, an editor at Chemistry World magazine published by the Royal Society of Chemistry, said the concept is clearest when people look at hands as mirror images, according to the Royal Society of Chemistry. He said molecules that are mirror images can act very differently in biological systems that themselves have handedness, according to the Royal Society of Chemistry.

Broadwith said the awarded work addresses control over which “hand” chemists make, according to the Royal Society of Chemistry. That control matters for products such as drugs and also for flavors and fragrances, according to the Royal Society of Chemistry.

The Academy pointed to thalidomide as an example of harm from the wrong variant, according to AFP. Thousands of children were born with birth defects in the thalidomide episode in the late 1950s and early 1960s, according to AFP. Researchers later concluded that the active substance’s mirror image caused the harm, according to AFP.

Science magazine reported that chemists often use a chiral catalyst, a substance that accelerates a reaction without being consumed while favoring one mirror-image product. That broader approach, known as asymmetric catalysis, was recognized with the 2001 chemistry Nobel to William Knowles, Ryoji Noyori and Barry Sharpless, according to Science magazine and AFP.

Kagan’s 1986 nonlinear effect

Kagan took the first decisive step in 1986 by discovering a new way of manipulating chemical reactions, according to NobelPrize.org. The method allowed him to create a larger excess of one mirror image than had previously been considered possible, according to NobelPrize.org.

Science magazine reported that chemists had assumed catalysts would need to be almost entirely one-handed to make equally pure one-handed products. In 1986, Kagan showed that assumption was not always correct after mixing catalysts containing ligands of different handedness, according to Science magazine.

Even a small excess of one catalyst form could generate a much larger excess of one-handed product, a phenomenon known as a nonlinear effect, according to Science magazine. The Royal Society of Chemistry dated Kagan’s first decisive step to 1985 in its summary, while NobelPrize.org dated it to 1986.

Emmanuelle Schulz, director of the Institute of Molecular Chemistry and Materials of Orsay, said the work explained how asymmetric amplification can lead to only one molecular form, according to Science magazine. Schulz had collaborated with Kagan, according to Science magazine.

Erick Carreira, an organic chemist at ETH Zürich, said many reactions are now known to show nonlinear effects, according to Science magazine. The discovery proved useful in academic research and pharmaceutical work because chemists could pursue single-handed products without requiring chirally pure catalysts, according to Science magazine.

CNRS said Kagan’s work on nonlinear effects in asymmetric catalysis helped answer how molecular asymmetry could be amplified. CNRS said the Nobel Committee judged the discoveries decisive for chemists designing reactions for pharmaceutical manufacturing.

Soai’s autocatalysis breakthrough

Soai took the next step, according to NobelPrize.org. In 1995, a key publication described how he designed the first chemical reaction with the potential to be homochiral, according to NobelPrize.org.

In 2003, he succeeded by presenting a reaction in which only one of two possible mirror images was formed, according to NobelPrize.org. Apart from life itself, no one had previously achieved that result, according to NobelPrize.org.

Science magazine reported that Soai used a zinc compound reacting with a starting molecule without handedness to produce a chiral catalyst in either left- or right-handed form. The catalyst both accelerated the reaction and produced more of itself, a process called autocatalysis, according to Science magazine.

That created a feedback loop capable of amplifying a tiny initial excess of one mirror image, according to Science magazine. By 2003, Soai had advanced the system so that a small chance imbalance could snowball until more than 99% of the product shared the same handedness, according to Science magazine.

The Academy called the Soai reaction one of the most elegant chemical experiments ever conducted, according to AFP. Matthew Powner, an organic chemist and origin-of-life researcher at University College London, called it totally remarkable and said it was the only reaction he knew in which this happens spontaneously, according to Science magazine.

Matthew Fuchter, an organic chemist at the University of Oxford, said the Soai reaction became a prominent example because it demonstrated possibility, although comparably effective systems have been difficult to find, according to Science magazine.

Broadwith said the work may also suggest how chiral molecules on Earth, including proteins, sugars and biomolecules, came to favor one handedness, according to the Royal Society of Chemistry.

Shopping trip, reactions and Nobel week

Soai said he learned of the award while out shopping, according to Reuters. AFP reported that he was shopping for groceries when he received the call.

“This is the most exciting day in my life, I am very glad to share this prize with professor Henri Kagan,” Soai said, according to the Royal Society of Chemistry.

Soai also said chirality is essential and a prerequisite for the origin of life, according to the Royal Society of Chemistry. He said researchers were pleased to find an organic reaction relevant to homochirality, while adding that the result was not the final answer and the field should continue, according to the Royal Society of Chemistry.

“Our prize this year should make people recognise the importance of the chirality of molecules,” Soai said, according to the Royal Society of Chemistry. He said study of chirality should develop further for the next generation, according to the Royal Society of Chemistry.

Speaking in Tokyo, Soai thanked research partners, fellow researchers and students, according to AFP. He said the combination of faculty and students is crucial in experimental science and that he had met truly wonderful people, according to AFP.

French President Emmanuel Macron congratulated Kagan on X and called the achievement a tremendous source of pride for France, according to AFP.

Robert Mokaya, president of the Royal Society of Chemistry, congratulated Kagan and Soai and said asymmetric organic synthesis shows how fundamental chemistry can support solutions to major societal challenges, according to the Royal Society of Chemistry. Mokaya noted the link to effective medicines and welcomed recognition of Kagan’s contributions 25 years after the 2001 asymmetric-synthesis prize, according to the Royal Society of Chemistry.

The chemistry announcement followed the week’s medicine and physics awards, according to Reuters. AFP reported that the physics prize honored Belgian physicist Francis Halzen for work using Antarctic ice to capture particles from the distant cosmos.

AFP reported that the medicine prize honored U.S. psychiatrist and neurologist Karl Deisseroth and German scientists Peter Hegemann and Georg Nagel. AFP reported that the literature laureate was scheduled for Thursday, the peace prize for Friday and the economics prize for Oct. 12.

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